The Mk 10 torpedo,
designed for the R- and S-class submarines, was first introduced in 1915,
and had been developed by the Newport Torpedo Station and Bliss in a joint
venture. It replaced the earlier Mk 7, and greatly increased submarine
torpedo dimensions.

The Mk
10 remained the only torpedo suitable to the S-class submarines, their
short tubes preventing the use of Mk 14 torpedos. They were not the only
submarines to use this weapon, however -- fleet submarines, during the
1942 torpedo crisis, used the Mk 10 as a substitute for the regular Mk
14. A number can be supposed to have been handed over to the British when
several S-class submarines were transfered.

Despite
its age the Mk 10 was the most effective U.S. torpedo of 1941 / 1942, causing
the loss of the heavy cruiser Kako off Kavieng on August 9th 1942
as the peak of its career. It was not retained after the production difficulties
of the Mk 14 had been corrected.